Rectifier



Mach 1, 1949. M. F. sKlNKER 2,462,911

RECTIFIER Filed Oct. 20, 1945 ATTO Y Pyatentecl l, 1949 Federal Telephone and Radi o Corporation,

" Newark, N. J., a corporation of Delaware v 'Application October 20, 1945', Serial No. 623,561

3 Claims. (Cl. F15-366) The present invention relates to arrangements for cooling rectiflers, particularly those which are mounted in closed housings or cans.

The dangers and limitations of heatdevelopment during the operation of rectiers has been recognized before, andmeans have been provided to dissipate the heat formed during operation of the rectifier. One of such means are iins each arranged next to one or a plurality of rectifier discs in a stack.

Difficulties arose in such cases where the rectier stacks had to be mounted in closed housings .or cans in order to protect them from the atmos- Figure 1 is a partial longitudinal sectional viewl through a rectifier stack mounted in an enclosed housing;

Fig. 2 is a sectional view along the lines 2--2 of Fig. l;

Fig. 3 is a longitudinal sectional view of another embodiment of mounting the cooling iins arranged inside of the housing;

- ring and a preferably squarely shaped inner fin Fig. 4 is a sectional view along the lines -t of Fig. 3;

Fig. 5 is a partial longitudinal sectional View of still another embodiment of arranging the cooling iins inside the housing;

Fig. 6 is a sectional view along the lines 6 6 of Fig. 5;

Fig. 7 shows an end view of the arrangement of mounting the outer cooling fins on the housing containing the rectifier stack; and

Fig. 8 is a front view of the arrangement shown in Fig. 7.

Referring now to the drawings, Figs. 1 and 2 disclose one embodiment of mounting the inner cooling fins in the rectifier stack. The rectifier stack I comprises in usual manner a central bolt 2 which is surrounded by an insulating tube 3. A number of rectiiier discs 4 are stacked on the insulating tube 3 and each disc Il is spaced from the next adjacent disc by a metal ring 5 having flange-like extensions at both ends; thereby providing series connection between adjacent discs. Two insulating washers 6 are inserted into the 'I mounted between the two washers 6.' The outer ends I of the ns 1 are bent over for about 90 along the inner face of housing 9 in order to provide a spring-like support for the fins on the inner side of the housing 9 containing the entire rectifier stack. A predetermined number of rectiiier discs 4 with`cooling ns 'I arranged between them, and lugs 8 as terminals for a predetermined number of rectier-s are mounted to a stack in the housing 9, which stack is kept in position by a nut Ill screwed on the bolt 2. The housing 9 is then lled up with any heat dissipating liquid medium, preferably oil, which greatly increases the heat conductivity to the housing 9.

In order to assure further heat dissipation from the housing 9 a number of preferably squarely shaped outer ns il are provided on the outside of the housing 9.3 each fin being on its inner end bent over about along the outer surface of the housing 9 to an extension l2 which keeps each one of the fins lI by a spring-like action in its position.

Whereas Figs. 1 and 2 disclose one embodiment of mounting of the fins, Figs. 3 and'4 show a different embodiment of such mounting. According to this second embodiment a washer I3 is arranged between each pair of adjacent rectier tween each pair of adjacent rectier discs i. The outer ends l of theiins I are again bent over about 90 along the inner surface of the housing 9 in order to insure a spring-like action against the housing 9 thus retaining each iin 'I in its proper position. Preferably two pairs of insulating washers I4 and I5 in opposite arrangement are provided near the outer end of the discs II which are adapted to space the discs 4 from the n I and to retain the latter in position. The ns 'l are equipped with a center hole of larger diameter than that of the washers I3 in order to avoid `electric contact between the two elements.

A rivet I6 oreyelet or the like penetrating the two washers and the fin 1 keeps the washers in proper position. Y

Figs. 5 and 6 of the drawing discloses still a further embodiment of the mounting of the inner fin I in the rectifier stack. The iin 'l is provided in this construction on one side with an insulating layer Il, since in accordance with this construction the inner cooling iin 'I is arranged very close to the disc 4. A metal washer I8 is provided between each pair of adjacent discs 4. The fin 'I is positioned varound the washer I8, however, due to a center hole I9 in the iin 1 of larger diameter than the outer diameter of the washer I8 a contactbetween the washer I8 and the fln 1 is avoided?, The outer end 'I' of the iin 1 is again bent over for about 90 along the inner face of the housing 9 in order to retain the n I in its proper position. A part of the inner fin 1 close to the outer end of the disc 4 is cut out and bent over about 180 in order to form a U-shaped end 20 for a-part of its width. The leg of the U- shaped end 20 is kept short, so that no contact with the counter-electrode can occur. v' Thus the U-shaped end 20 covers a selenium covered portion of the margin of the disc 4, the latter there- -by contributing in keeping the inner n 'I in its proper position.

It is to be understood that Figs. 3, 4 and 5, 6, respectively, show two further embodiments of the arrangements of the inner n and though no outer fins are shown in these figures, such outer fins can be provided as disclosed in Figs. 1, 2 or 7 and 8.

Figs. i and 8 show a particular construction of outer ns made of sheet metal. In order to provide the outer ns in accordance with Figs. 7 and 8 a sheet metal strip is iirst bent to U-shaped cross-section and then bent three times for 90 at a dist-ance conforming with the height and the width of the housing 9, thereby surrounding this housing on all four sides as clearly `shown in Fig.

'7.`r Before the bending operation takes place sev-- eral upwards extending portions of the U-strip are cut on proper places and turned back to the base of the U thereby providing a number of sideward extensions 2l which serve as 4spacing means between two adjacent outer n strips I I. The sideward extensions are arranged at such a distance in the U-shaped strip that upon bending the strip they cover three corners of the housing 9. The two ends of the strip, Where also side extensions 2| are provided, are bent outside for about 45 and form thereby parallel extending ends 22 which can be connected by a rivet 23 or the like. Thus each one of the strips surrounding the housing 9 and forming the outer fins II is retained in proper position.

While I have disclosed the principles of my in- 4 said discs and ns, one of said inner cooling iins being arranged between each pair of adjacent rectifier discs, la ring having flanges between each one of said discs, two washers of insulating material in said ring, said cooling iin held between said washers, the outer end of said fin bent over for about and extending along the inner face of said housing.

2. In a rectifier stack, a center bolt, 'a plurality of rectifier discs and inner cooling fins mounted on said bolt, and a housing surrounding said'discs and ns, one of said inner cooling flns being arranged between each pair of adjacent rectifier discs, a pair of washers between said discs, said fin being arranged between said washers, the outer end of said fin'bent over for about 90 and extending along the inner face of said housing fand at least two pairs of washers arranged on both sides of said n near the margin of said discs, said last mentioned washers adapted as spacing means for each pair of ad jacent discs. f 3. In a rectifier stack, a center bolt, a plu rality of rectifier discs and inner cooling iins mounted on said bolt, and a housing surrounding said discs and ns, one,of said inner cooling fins being arranged between each pair of adjacent rectifier discs, a metal washer arranged lbetween said pair of discs, a 1in positioned around said washer, said n having a. center hole of larger diameter than that of said washer, an insulating layer on one side of said fin, the outer end of said iin bent over 'about 90 and extending along the inner face of said housing, one portion of -said n near its outer end cut out and bent over twice for about 90 in order'to form a U-shaped part surrounding the margin of the said disc.

MURRAY F. SKINKER.

REFERENCES CITED `The following references are of record in the iile of this patent:

UNITED STATES PATENTS Number Name Date 1,051,481 Bradley Jan. 28, 1913 1,504,002 Thompson Aug. 5, 1924 2,288,341 Addink June 30, 1942 2,326,151 Marbury Aug. 10, 1943 2,349,629 Lazich May 23, 1944 FOREIGN PATENTS Number Country Date 51,318 Netherlands Sept. 16, 1941 693,239 Germany July 6, 1940 

